Means for overcoming static disturbances in telegraphy



(No Model.)

Q. SELDEN.

MEANS FOR OVERGOMING STATIC DISTURBANGES IN TELEGRAPHY.

No. 309,571. Patented Dec. 23, 1 884.

WITNESSES 5 uvvnvroz; v m ghyw J I By his Afforney v I To all whom itmay concern Warren rams CHARLES SELDEN, OF

MEANS FOR OVERCOMING STATIC SPECIFICATION forming part of Letters PApplication filed Novem sr. Louis, MISSOURI.

DISTURBANCES lN TELEGRAPHY.

atent No. 809,571, dated December 23, 1884.

her 11, 1862. (No model.)

Be it known that I, CHAS. SELDEN, a citizen of the United States, and aresident of St. Louis, in the county of St. Louis and State of Missouri,have invented certain new and use ful Improvements in Telegraphs, ofwhich the following is a specification.

The object of my invention is to prevent the occurrence of false signalsin telegraph apparatus from the discharge or return current which flowsthrough the relay when the battery is withdrawn from line and the lineput to earth.

My invention consists in the combination, with the relay-armature, of anauxiliary electro-magnet arranged to exert a pull upon the same inopposition to the relay-coils when affected by the discharge or returncurrent, in combination with suitable means for including the coils ofsaid magnet on a local circuit with a battery at the instant of thestatic discharge, so that simultaneously with the flow of thedischarge-current the current of the local battery shall flow in closedcircuit through the coils of the auxiliary electro-magnet.

In setting forth the principles of my invention I have shown the same asapplied to the differential relay of a duplex or multiplex telegraph;but I do not by any means limit myself to such application. I have alsoshown and described one kind of device that may be employed for bringingthe auxiliary magnet into action; but I do not limit myself to theparticular device described, the essence of my invention consisting inovercoming the effect of the return or discharge current by an an);-iliary magnet arranged to pull in mechanical opposition to the relay,and brought into action at the proper time by any suitable automaticdevice acting synchronously with the movements of the transmitter toclose the circuit of the local battery through it.

In the accompanying drawings, Figure 1 is a diagram of the apparatus atone station of a duplex telegraph, showing one method of carrying myinvention into practice. Figs. 2, 3, 4: show the auxiliarycircuit-closinglever of Fig. l in detail. Fig. 5 shows a device that maybe used for modifying or adjusting the duration of the opposing effectsof the auxilidevice shown in Fig. 5. Figs. 7 and 8 show a second methodof closing the circuit of the auxiliary electro-magnet.

It indicates an ordinary differential relay, one of whose coils is inthe main-line circuit, while the other or equating coil is in a circuitto earth containing the adjustable resistancerheo.

A indicates the transmitter-lever, which is operated by eleetro-magnetF, controlled by a key, G, and local battery H.

At T are shown the adjustable stops for the leverA. At the opposite endof the lever is the insulated contact-spring 0, arranged to come intocontact with adjustable point a, so as to put the main line battery M Bto line through said point a and spring 0 when the transmitter isoperated. Normally the spring rests in contact with the hook on the endof lever A, which latter, being connected with earth, serves to completethe circuit between line and earth when the battery is taken off.

These devices being well known in the art, their operation need not bedescribed in detail.

S is the reading-sounder in a local circuit, controlled in the ordinaryway by the armature-lever of the relay. Said armature-lever is indicatedat E, and is provided with two armatures, one of which is acted upon bythe core of relay R, while the other is the armature for the auxiliarymagnet D, which serves, when energized, to counteract the pull of therelay-magnet when the discharge or return current circulates in thelatter, and is for that purpose energized through the intervention ofdevices to be presently described. The core of magnet D is by preferenceadj ustable to and from the armature-lever for the purpose of modifyingthe strength of its pull to correspond with the strength of thedischarge or return current from the line circulating in the coils ofthe relay.

K is a local battery in circuit with magnet D and controlled by a lever,B, a contactspring, m, upon which serves to complete the circuit of thelocal battery through a'contactstop, 0, when lever B is operated.

At T is shown the adjustable stop for said lever, while rheo indicates arheostat for my magnet. Fig. 6 is a modification of the modifying thestrength of the magnet when energized by the local battery. The lever Bis an auxiliary lever to the transmitter-lever A, and is provided with ahinged or jointed portion, B, against which the stud or pin 1? on leverA impinges whenever the transmitter is operated, the construct-ion beingsuch that the hinged portion will allow the stud to slip by withoutmoving the lever B during upward movement of the transmitter A-th at is.when said transmitter acts to put the main battery to line but thatduring the return movement of the transmitter to its normal position thestud will operate said lever B and cause a momentary closing of thelocal circuit which charges the auxiliary magnet, this closure occurringat the time that the main battery is withdrawn from line 7 and the lineis put to earth. The construction of this portion of the apparatus isshown more clearly in Figs. 2, 3, and 4. As here shown, the portion B ishinged or jointed at b and has a shoulder or step at d, which isnormally held in engagement with B by a spring f. The portion B can beraised into the position shown in Fig. 3 without disturbing B; but whenB is carried downward the lever B moves with it, and its opposite end israised from its back stop and closes the local circuit of the batterywhich directly or indirectly serves to energize the auxiliary magnet.

Fig. 4 illustrates the relative position and action of the parts. Theend of stud P moves in the arc of a circle, w, described from thefulcrum of the transmitter-lever A. The part B of the auxiliary lever,when moved upward by 1?, moves in the arc of a circle, y, described fromits joint I) as a center, so that l in moving upward will escape it at apoint, 3, where the arcs intersect, and B will immediately rcturn toitsnormal position. In this movement of the transmitter, by which movementthe battery is put to line, no movement is imparted to the auxiliarylever B, and the auxiliary magnet D therefore remains unaffected. As thetransmitter returns to its normal position, I engages with the upperside of B, carrying the latter, with lever B, downward, so as to causethe local circuit to be closed at the same time that thedischarge-current flows in the relay. The armature-lever E is thus heldin its proper position by the auxiliary magnet acting in opposition tothe attraction of the relay-coils.

In the movement of the lever B in chargingv the auxiliary magnet thepoint of B moves in the are of a circle, and the end of 1 escapes by itat a point, 2, where arcs a: and z intersect, this point being above thepoint at which 1 comes to rest and resumes its normal position prior toanother movement upward. The contact stops and springs are properlyadjusted so that the local circuit of I) shall be closed at m c at theinstant that the main-line battery is withdrawn and the line connectedtoearth at 0 n. The duration of the contact at m e, and the consequentduration of the opposing effect of the auxiliary magnet, maybedetermined by suitable adjustment of 0, so that said opposing effectwill continue during the period that the return-current exercises adisturbing effect; or said adjustment may also be partially effected bymoving the ad justable point P out or in, so as to vary the time duringwhich it shall hold the spring m in contact with c.

The device shown in Figs. 2, 3, and 4 forms the subject of anotherapplication for patent filed by me, and I therefore do not make anyclaim to it herein.

Other devices might be used in place of the particular devices shown formomentarily causing the charge of the auxiliary opposing magnet byclosing the circuit of the local battery through it at the same timethat the discharge or return current flows in the relaycoils, and I donot, therefore, limit myself in this respect.

A device that may be used in place of the auxiliary lever described forclosing the circuit of the auxiliary magnet is shown in Figs. 7 and 8.It consists of a circuit-closing spring. 6, attached to thetransmitter-lever A, or to any device operated thereby, and an inclinedpiece, 5, of some insulating material, upon the face of which is aconductingpiece with which the spring makes contact on its returnmovement only. On the upwardmovement of the lever the toe on the end ofthe spring rides along the back of the inclined piece 5, and escapes byits top edge, assuming then a position in substantially the samevertical line with its original or lowest position, so that on thereturn movement it slides 011 the face having the contact-plate, and,slipping by thelower edge of the piece 5, resumes its original position,shown in the drawings, ready for the next up and down movement. Thespring 6 and the plate form the terminals of the polarizing-circuit. Thepiece 5 may be made adj nstable by any suitable mechanical device, so asto determine the instant at which the circuit shall be closed. The'adjListing-screw indicated in Fi 8 as employed for this purpose is omittedfrom Fig. 7 for the sake of simplicity.

A device that may be used for adjusting the period of the opposinginfluence of the auxiliary magnet to correspond with the period of thereturn or discharge current is shown in Fig. 5. It consists of a mass ofsoft iron, 12', adjustable to and from the core of D, so as to in effectvary the magnetic mass, and the consequent readiness with which the'coreof I), having been momentarily charged, will lose its charge. The nearerthe bar 12 to the core the slower is the discharge, and hence the timeduring which the opposing effects of D shall endure may be adjusted tocorrespond more or less closely with the time during which thereturn-current would, if unopposed, exert a disturbing effect. Anequivalent method to that shown in Fig. 5 consists in bridging, to agreater or less extent, the

poles of the magnet I). Such method is shown in Fig. 6, in which 13indicates a bar of iron adjustable to and from the poles of D, so as tocomplete, to a greater or less extent, the magnetic circuit.

My invention is designed, chiefly,t'or use with the receiving-relays ofduplex or multiplex telegraphs, but may be used in other connections, asis obvious.

The auxiliary circuit-closing lever of Figs. 1, 2, 3, and 4 forms thesubject of claims in an application for patent filed by me November 11,1882, No. 76,568, and no claim is therefore made to it herein per s0.

\Vhat I claim as my invention is- 1. Thecombination,with thearmature-lever of a rcceiving relay, of an auxiliary magnet arranged toexert a pull on said armature lever in opposition to the'coils of therelay when affected by the discharge or return current, and suitablemeans for closing the circuit ot a local battery through said auxiliarymagnet simultaneously with the flow of the discharge or return currentthrough the coils of the relay.

2. The combination, with a relayarmature, of an auxiliary electro-magnetarranged to exert a pull upon said armature in opposition to the pull ofthe relay-magnet when aii'ected by the discharge or return current, alocal circuit and battery for said magnet, and means for closing saidcircuit through the auxiliary electro-magnet on the back movement of thetransmitter only, said circuit being unaffected on the forward movementthereof.

0. The combination, with an auxiliary electro-magnet, D,of asupplemental circuit-closer controlling the circuit thereof, atransmitterlever, and a spring-joint connection, 13, interposed betweenthe transmitter and the supplemental circuit-closer, so as to allow saidtransmitter to put the main battery to line without affecting thecircuit-closer, but to cause the transmitter to operate thecircuitcloser when said transmitter returns to its normal position.

4. The combination of the auxiliary magnet D in local circuit,circuit-closer B B, constructed asdcscribed, and transmitter-lever A,carrying the adjustable stud l.

Signed at New York, in the county of New York and State of New York,this 9th day of Xovember, A. l). 1882.

CHAR-LES SELDEN.

Witnesses:

THOS. TOOMEY, Gno. G. COFFIN.

